The key physical-chemical processes determining the Composition and Temperature of (exo)planetary atmospheres

• Applicants: Professor Dr. Ansgar Reiners; Dr. Miriam Rengel
• Subject Area: Astrophysics and Astronomy
• Term: from 2017 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 362460241

Characterizing the atmospheres of extrasolar planets is a new frontier in exoplanetary science, and as such is dependent on observations and interpretation toolkits. This project will develop a novel strategy for addressing a key question in current exoplanetary atmospheric research: what are and how do the key chemical and physical processes determine the atmospheric composition and temperature of exoplanets? Hence, the main objective is to assess if the inclusion and combination of the different physical and chemical mechanisms of planetary atmospheres into the predictions can lead to a comprehensive understanding of planetary atmospheres, considering observations as a key to validation assessment. These issues have only been poorly understood so far, because observational data is still too sparse, present sources of uncertainties and compositions are largely unexplored, and, finally, models are limited by the physical and chemical treatment and lack of accurate predictions. The project will focus on five different levels of understanding: (1) Extending existing planetary atmospheric tools to exoplanets to incorporate the key physics and chemistry into the model; (2) re-analysing archival data as well as detecting atmospheres by new spectroscopic observations with current and near-future facilities -- including higher sensitivity and simultaneous wider coverage of the spectral range offered by VLT/CRIRES+, for which we use guaranteed time-- employing noise reduction, telluric correction analysis and algorithms for searching weak signatures in the data; (3) comparing the observations with the models to investigate which physical and chemical processes are most important; (4) determining the composition and temperature profiles of the observed well-defined selected samples; (5) generating a comprehensive library of templates of selected theoretical spectra of extrasolar planetary atmospheres. The multidisciplinary nature of the project is strong, involving a combination of well-developed astronomical, physical, chemical and computational tools and algorithms.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1992: Exploring the diversity of extrasolar planets